The object of the present invention is means for enhancing the value of distillation residues of fermentation products and in particular, a process for producing compounds of economic interest from these distillation residues of fermentation products. This production process also comprises suitable steps for extracting these compounds.
The invention is particularly concerned with enhancing the value of distillation residues of fermentation products from the agro-feeding industry. Within the scope of the invention, these residues or byproducts are used as substrates for growing microorganisms capable of developing and producing molecules of an economic interest; these compounds are in particular high added value molecules such as fragrances, dyes, enzymes, amino acids, lipids, carbohydrates, biologically active products in the therapeutical, agrofeeding field or for agriculture, etc.
FR 2 705 971 describes a process for producing R-xcex3-decalactone comprising growing microorganisms of the Sporidiobolus or Fusurium genus in a culture medium containing a precursor of R-xcex3-decalactone selected from ricinoleic acid , lesquerolic acid or salts or esters of these acids with C1-C3 alcohols. Extraction of the produced R-xcex3-decalactone is performed during the growing process, with an extraction solvent, immiscible with water.
The inventors within the scope of this invention have observed that residual products from wine distillation, and in particular that of cognac wine (in this specific case, these residual products are referred to by the expression xe2x80x9cdistilling slopsxe2x80x9d), are able to form suitable substrates for growing microorganisms, in order to produce molecules of an economic interest.
Accordingly, the object of the present patent application is a process for preparing compounds of an economic interest from substrates comprising or including distillation residues of fermentation products and the use of microorganisms for applying this process. The object of the present application is also a process for extracting the produced compounds, wherein said process is advantageously combined with the production process. Thus, the provided extraction steps according to the invention may follow the production phase(s) of the compounds or be integrated into this phase. If required, conditions selected for the extraction are determined according to their influence on the production of the compounds, for example on the production yield.
Hence, the invention relates to a process for preparing compounds of an economic interest (called xe2x80x9ccompoundsxe2x80x9d), comprising the steps of:
a) growing under aerobic fermentation conditions, at least one microorganism selected for its capability of synthesizing said compounds, in presence of a substrate comprising a residue from the distillation of fermentation products.
b) recovering the produced compounds.
The object of the invention is in particular a process for producing fragrant volatile compounds (or fragrances).
Advantageously, the invention provides a process which allows natural fragrances to be formed.
For the growing step, fermentation may be carried out in an aerobic, anaerobic or dual medium. The implemented substrate for applying the process comprises for example, a residue from the distillation of fermentation products from plant organs (roots, tubers . . . ) or more generally from plant portions.